1. Field of the Invention
The present invention relates generally to suspended ceiling grid structures and, more particularly, to a grid structure with main runners incorporating an extending and measurement indicia scheme along a predetermined border portion of the main runner, and at either or both opposite ends thereof. The measurement indicia scheme of the present invention provides the grid structure installer with the capability to very quickly establish a previously determined and correct border dimension for the subsequent installation of an engaging cross runner, and such as is desired to provide consistent and equal borders along opposite extending ends of the room enclosure within which the grid structure is installed.
2. Description of the Prior Art
Suspended structures for creating ceiling grids are fairly well known in the art, the concept behind such structures being to provide suspended support for ceiling tiles. The tiles are typically rectangular shaped and acoustically insulating in nature and function to recreate a uniform and xe2x80x9cdroppedxe2x80x9d ceiling appearance to an interior enclosure with an unfinished ceiling, such enclosures including commercial building interiors, as well as basement ceilings in residential dwellings.
U.S. Pat. No. 4,677,802, issued to Vukmanic, discloses one known arrangement of suspended ceiling system and runner and which is characterized by each of the runners being composed of a first member and a cap member. The first member is bent to form an inverted T-bar configuration with a groove extending inwardly from the flange of the T and the cap member having the same configuration and being secured on the flange of the T-bar configuration to form a channel with flange portions on each side for supporting panels of the ceiling system.
U.S. Pat. No. 4,712,350, also issued to Vukmanic, discloses a centering arrangement for T members of a suspended ceiling for holding a plurality of panels supported by the runners in a desired position on the flanges of the runners. The centering arrangement includes a bump extending from each side of a cross sectional web profile of the runner, the bump being formed in the web immediately adjacent a cut in the runner so that the drawing of the material into the bump will not draw material from the flange or adjacent thereto. The bump shape is preferably xe2x80x9chalf-moonxe2x80x9d or semi-circular in configuration and so that it provides a smooth camming surface for both lateral movement of the panel along the flange as well as vertical movement towards the flange.
U.S. Pat. No. 4,525,973, again issued to Vukmanic, teaches a suspended ceiling system again teaching main runners and cross runners which are inter-engageable to define a rectangular grid system. Suitably configured and elongated apertures are formed in the webbed profile of the main runners in axially spaced apart fashion and which receive an appropriately configured connecting end of selected cross runners and so that the cross runners are engaged to the main runner in mutually engaging fashion and on opposite sides thereof. Additional examples of suspended ceiling grid systems are illustrated by the likes of U.S. Pat. No. 4,470,239, issued to Sauer, U.S. Pat. No. 4,727,703, issued to Platt, and U.S. Pat. No. 5,839,246, issued to Ziegler.
The present invention discloses a grid structure with main runners incorporating an extending and measurement indicia scheme, along predetermined border portions thereof. As previously explained, the measurement indicia scheme of the present invention provides the grid structure installer with the capability to very quickly establish a previously determined and correct border dimension for the subsequent installation of an engaging cross runner, and such as is desired to provide consistent and equal borders along opposite extending ends of the room enclosure within which the grid structure is installed.
An extending end portion of a main grid runner is illustrated, the main runners typically measuring an overall twelve (12xe2x80x2) feet in length according to industry standard. The main runner again includes such general structural features, when illustrated in cross section, as a tile support lip, a web extending from a midpoint of the lip and defining first and second opposite faces, a thickened upper edge, and a connector clip.
The main runner also includes a plurality of individual and elongated channels formed through its faces and at axially spaced apart intervals. The channels are each configured for receiving, in interconnecting fashion, a connector clip associated with an extending end of a cross tee. The main runners further include such channels configured at a dimension of 3xe2x80x3 from a given end and opposite end location (exclusive of the connector clip) and at further equal six (6xe2x80x3) inch intervals extending therebetween and across the entire intermediate length of the main runner.
The interconnection scheme of the spaced and parallel extending main tees, along with the cross wise extending tees, defines the interconnecting grid structure for subsequent installation of ceiling tiles. According to the conventional art, two (2xe2x80x2) and four (4xe2x80x2) foot spaced cross tees (and corresponding 2xe2x80x2xc3x972xe2x80x2 or 2xe2x80x2xc3x974xe2x80x2 tiles) are employed in assembling and completing the grid structure.
As is also known in the relevant art, room measurements rarely, if ever, even out to provide equidistant dimensions established between opposite and parallel extending border locations of the grid structure. Typically, the installer is then required to undertake additional measurement and sectioning of the main runners (through the use of a tape measure typically) to achieve the desired and equidistant dimensions and before installing the main runners. It is also conventionally known that an equidistant distance to be achieved for each of two opposite border locations will either fall into a dimension of less than 48xe2x80x3 (four feet) or 24xe2x80x3 (two feet), based again on whether 2xe2x80x2xc3x972xe2x80x2 or 2xe2x80x2xc3x974xe2x80x2 tiles are to be utilized. The main runner indicia scheme provides the installer, once he or she has previously determined the overall required length of the room enclosure and the required dimension for establishing the equidistant and opposite extend borders, with the ability to immediately proceed with sectioning an exact portion from the end of the main runner, utilizing the imprinted indicia scheme.
The indicia scheme includes a plurality of half inch incremental markings extending from the end of the main runner to a location six inches inwardly. The first three (3xe2x80x3) elongated channel is located, naturally, at the midpoint of the six (6xe2x80x3) inch indicia scheme and is considered to function as a primary reference point for determining a desired sectioning distance. The next succeeding and elongated channel is located in actuality a distance of nine (9xe2x80x3) inches from the end location of the main runner, however it is, for present purposes, considered only to be a secondary reference point of an additional six (6xe2x80x3) beyond the primary reference point.
As is again known, all succeeding and intermediate extending channels are at identical and six (6xe2x80x3) increments, such that a desired subset group of these elongated channels iterate (in inches) as follows: 3; 6; 12; 18; 24; 30; 36; 42 and 48. For purposes of measuring and establishing the equidistant border layout, reference is not necessarily made to the six inch markers beyond 48xe2x80x3 (such as at 54xe2x80x3, 60xe2x80x3, . . . ) since this range will fall into areas designated for placement of full sized tiles.
The present invention further takes advantage of the fact that only plus or minus variations of six inch increments need to be considered when determining where to section the main runner for equidistant placement of the border extending cross runners, these again being accounted for by the primary reference point, the next succeeding six inch spaced secondary reference point, and the 0-6xe2x80x3 measurement indicia scheme. By example, the desire to establish a thirteen (13xe2x80x3) inch border at each end of the assembled main runner(s) requires only the installer to proceed to the primary reference point (considered to equate to 6xe2x80x3, 12xe2x80x3, 18xe2x80x3, etc., distances), beyond which the installer counts out an additional one (1xe2x80x3) inch towards the exposed end of the main tee.
In a further example, by which the installer desires to establish seventeen (17xe2x80x3) inch and equidistant borders, the installer will then desirously select the secondary reference point (rather than the primary reference) due to the fact that an additional five (5xe2x80x3) inches (beyond the selected six inch increment to which each of the primary and secondary reference points equate, and in this case being twelve (12xe2x80x3) inches) is required and further due to the fact that only three (3xe2x80x3) inches exist beyond the primary reference point and the exposed end of the main runner. To quickly complete the measurement, and subsequent sectioning act, the installer designates the second reference point as equating twelve (12xe2x80x3) inches, then adds five (5xe2x80x3) additional inches in a direction towards the primary reference point, this further immediately resulting in the installer jumping to the primary reference point and counting back one (1xe2x80x3) inch towards the secondary reference point, at which point the runner is sectioned and the resulting and overall running length of the main runner, or plurality of interconnected runners, is such that an equidistant 17xe2x80x3 is provided at each opposite end of the assembled main tee.
The border measurement and indicia scheme of the invention may also advantageously utilize the marking system incorporated into the main runners for the identification and proper location of the cross runners prior to engagement of the connector clips within the main runner channels. Specifically, the color coding variation of the underlying marking system can be utilized by the installer in quickly establishing reference points (typically within the 24xe2x80x3 or 48xe2x80x3 ranges of each opposite main tee end) and for counting back to the primary and/or secondary reference points and border indicia scheme.
A further feature of the present invention is the provision of a diagonal ruler marking at a selected distance along the main runner. The purpose of the selected marking is to provide a standard for measuring both diagonal distances of a standard 2xe2x80x2xc3x974xe2x80x2 grid and to ensure the establishment of a perfectly configured rectangle.